Riveted joints: Rivets are generally specified in practice by which primary dimension?
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AThickness of plates to be joined
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BOverall length
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CShank diameter
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DDiameter of head
Answer
Correct Answer: Shank diameter
Explanation
Introduction / Context:Standard practice for specifying fasteners ensures correct selection and interchangeability. For rivets, the shank diameter governs hole size, pitch, and joint efficiency and is therefore the primary specification.
Given Data / Assumptions:
- Conventional hot or cold-driven rivets used in plate joints.
- Holes are drilled/punched to suit the rivet shank diameter plus clearance.
- Other dimensions (length, head size) follow standards once the diameter is set.
Concept / Approach:The rivet's shank diameter determines net-section area of plates and the shear capacity of the rivet itself. Designers first choose diameter to meet shear and bearing requirements; length is then chosen to accommodate grip length and head formation.
Step-by-Step Solution:
Select rivet diameter d from strength checks (shear of rivet, bearing on plate, net tension of plate).Choose hole diameter typically d_h ≈ d + clearance (manufacturing standard).Select rivet length to suit total grip plus allowance for forming head.Finalize head type per standard (e.g., snap, pan, counter-sunk).Verification / Alternative check:Joint design tables list capacities primarily by shank diameter, confirming it is the controlling specification in catalogs and standards.
Why Other Options Are Wrong:
- Plate thickness: used to pick length, not the primary rivet designation.
- Overall length and head diameter: derived after diameter selection.
Common Pitfalls:Specifying length without confirming grip range leads to improper set and reduced strength.
Final Answer:Shank diameter